The Amazing Rangia Clam
Did you know that Lake Pontchartrain isn’t really a lake? It is an Estuary, making it one of the most productive natural habitats in the world. Fish, frogs, snakes, blue crabs, migratory birds, river otter… they all need our Lake in order to thrive.
Our lake is also home to a special clam known as the Rangia Clam (Rangia Cuneata). In early history the Rangia was a non nutritious food source for the early Native Americans around the Lake. They would discard the empty clam shells in the same refuse pile leaving behind evidence of their campsites in locations known as Middens. There are a couple of locations along our adventure path on Cane Bayou.
In the early 1930’s Rangia Clams became dredged for uses such as driveways, roadways, parking lots, levees, and the production of cement. The harvest of the clams yielded a gross annual value of $34 Million for the industry in the 1980’s.
However, in the late 1970’s the turbidity of the lake became dense and grossly polluted prompting the lake to be closed to swimming. The amount of Rangia clams left to filter out pollutants wasn’t enough to keep the volume of the lake clean and clear.
In 1990 the harvesting of Rangia Clams was banned and rather quickly the clam population and the water quality began to rebound. It is estimated that today there are around 400 clams per square meter that can filter the volume of the lake in about 4 days! As the healthy clams die off they leave behind their empty shells making the lake bottom even healthier for fish habitats.
Rangias could be considered a keystone species in the fact that their numbers play a huge role in the environment and without them Lake Pontchartrain wouldn’t be the thriving ecosystem so many of us love and enjoy today. We have to give a big shout out to these little guys doing a huge job! 629 square miles of water is a lot to clean!